Techniques for routing from an endpoint with simultaneous associations to multiple networks

ABSTRACT

A node within a wireless endpoint device may be coupled to multiple heterogeneous networks simultaneously. The node is configured to select between the different networks based on various constraints associated with the endpoint device, applications executing on the endpoint device, traffic routed by the endpoint device, and constraints associated with the multiple networks. Based on these different constraints, and based on the current operating mode of the node, the node rates each network, and then selects the network with the highest rating to be used for routing purposes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional patentapplication titled “Method for Routing from an Endpoint withSimultaneous Associations to Multiple Networks,” filed on May 6, 2013and having Ser. No. 61/819,732, which is hereby incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention relate generally to wirelessnetwork communications and, more specifically, to techniques for routingfrom an endpoint with simultaneous associations to multiple networks.

2. Description of the Related Art

A conventional wireless endpoint device may be associated with manydifferent types of networks simultaneously. For example, a modernsmartphone typically includes a cellular transceiver capable of joininga cell network, as well as a WiFi™ transceiver capable of joining aWiFi™ network. Oftentimes the various different networks to which theendpoint device may be associated provide common functionality. In theabove example, both the cell network and the WiFi™ network would allowthe endpoint device to access the World Wide Web.

When coupled to multiple networks that provide common functionality,conventional endpoint devices oftentimes employ a rudimentary heuristicto determine which network to rely upon for specific tasks. Returning tothe smartphone example, a commonly used heuristic dictates that thesmartphone should always access the World Wide Web via the WiFi™connection as opposed to the cellular connection. This exemplaryheuristic is meant to prioritize usage of the WiFi™ network over that ofthe cellular network, because WiFi™ communication speeds are oftenfaster compared to cellular communication speeds.

One drawback of conventional heuristics for selecting between networksis that modern networks often provide varying levels of connectivity,and so prioritizing one network over another network can lead toconnectivity issues when the prioritized network provides limitedconnectivity. In the example of WiFi™ vs. cellular connectivity,wide-range WiFi™ networks now exist that are designed to support manyendpoint devices occupying a large geographical area, such as a shoppingdistrict or entire city. Such wide-range WiFi™ networks usuallysacrifice communication speeds for increased area of coverage and numberof users, thereby providing a large number of users with limited networkaccess. An endpoint device configured to implement the exemplaryheuristic described above would prioritize this wide-range WiFi™ networkover a cellular network, despite the fact that the cellular network mayactually provide better connectivity.

As a general matter, conventional endpoint devices often employheuristics for selecting between networks that, in certain cases, mayactually limit the communication abilities of the endpoint device.

As the foregoing illustrates, what is needed in the art is a moreeffective approach for selecting between multiple wireless networks towhich an endpoint device may be coupled.

SUMMARY OF THE INVENTION

One embodiment of the present invention sets forth acomputer-implemented method for selecting between heterogeneousnetworks, including acquiring a set of constraints associated with anetwork node, determining a current operating mode associated with thenetwork node, prioritizing the set of constraints based on the currentoperating mode to generate a set of prioritized constraints, generatinga first rating for a first network to which the network node is coupledbased on the set of prioritized constraints, generating a second ratingfor a second network to which the network node is coupled based on theset of prioritized constraints, determining that the first ratingexceeds the second rating, and causing the network node to transmit orreceive data on the first network.

One advantage of the techniques set forth herein is that the endpointdevice may select the optimal network on which to perform communicationsbased on a wider range of environmental and operational factors comparedto traditional approaches.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1 illustrates a network system configured to implement one or moreaspects of the invention;

FIG. 2 illustrates a network interface configured to transmit andreceive data within a mesh network, according to one embodiment of theinvention;

FIG. 3 illustrates a node within the network system of FIG. 1 coupled tomultiple heterogeneous networks, according to one embodiment of thepresent invention;

FIG. 4 illustrates an exemplary scenario where the node of FIG. 3selects between heterogeneous networks based on performance metricsassociated with each network, according to one embodiment of the presentinvention;

FIG. 5 illustrates an exemplary scenario where the node of FIG. 3selects between heterogeneous networks based on a hop count associatedwith each network, according to one embodiment of the present invention;

FIG. 6 illustrates an exemplary scenario where the node of FIG. 3selects between heterogeneous networks based on timing constraintsassociated with transmitting data across each network, according to oneembodiment of the present invention;

FIG. 7 is a flow diagram of method steps for selecting between differentheterogeneous networks associated with a node, according to oneembodiment of the present invention.

FIGS. 8A-8B illustrate data and processing engines implemented by thenode of FIG. 3 when selecting between heterogeneous networks accordingto an operating mode of the node, according to one embodiment of thepresent invention;

FIGS. 9A-9B illustrate exemplary data and processing engines implementedby the node of FIG. 3 when selecting between a WiFi™ network and acellular network according to a high-throughput operating mode,according to one embodiment of the present invention;

FIGS. 10A-10B illustrate exemplary data and processing enginesimplemented by the node of FIG. 3 when selecting between a WiFi™ networkand a cellular network according to a low-battery operating mode,according to one embodiment of the present invention;

FIGS. 11A-11B illustrate exemplary data and processing enginesimplemented by the node of FIG. 3 when selecting between a WiFi™network, a cellular network, and a multi-hop mesh network according to alow-latency operating mode, according to one embodiment of the presentinvention; and

FIGS. 12A-12B illustrate exemplary data and processing enginesimplemented by the node of FIG. 3 when selecting between a WiFi™network, a cellular network, and a multi-hop mesh network according to ahigh-reliability operating mode, according to one embodiment of thepresent invention.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth toprovide a more thorough understanding of the present invention. However,it will be apparent to one of skill in the art that the presentinvention may be practiced without one or more of these specificdetails. In other instances, well-known features have not been describedin order to avoid obscuring the present invention.

System Overview

FIG. 1 illustrates a network system 100 configured to implement one ormore aspects of the invention. As shown, the network system 100 includesa wireless mesh network 102, which may include a source node 110,intermediate nodes 130 and destination node 112. The source node 110 isable to communicate with certain intermediate nodes 130 viacommunication links 132. The intermediate nodes 130 communicate amongthemselves via communication links 134. The intermediate nodes 130communicate with the destination node 112 via communication links 136.The network system 100 may also include an access point 150, a network152, and a server 154.

A discovery protocol may be implemented to determine node adjacency toone or more adjacent nodes. For example, intermediate node 130-2 mayexecute the discovery protocol to determine that nodes 110, 130-1,130-3, and 130-5 are adjacent to node 130-2. Furthermore, this nodeadjacency indicates that communication links 132-2, 134-2, 134-4 and134-3 may be established between the nodes 110, 130-1, 130-3, and 130-5,respectively. Any technically feasible discovery protocol may beimplemented without departing from the scope and spirit of embodimentsof the present invention.

The discovery protocol may also be implemented to determine the hoppingsequences of adjacent nodes, i.e. the sequence of channels across whichnodes periodically receive payload data. As is known in the art, a“channel” may correspond to a particular range of frequencies. Onceadjacency is established between the source node 110 and at least oneintermediate node 130, the source node 110 may generate payload data fordelivery to the destination node 112, assuming a path is available. Thepayload data may comprise an Internet protocol (IP) packet, an Ethernetframe, or any other technically feasible unit of data. Similarly, anytechnically feasible addressing and forwarding techniques may beimplemented to facilitate delivery of the payload data from the sourcenode 110 to the destination node 112. For example, the payload data mayinclude a header field configured to include a destination address, suchas an IP address or Ethernet media access control (MAC) address.

Each intermediate node 130 may be configured to forward the payload databased on the destination address. Alternatively, the payload data mayinclude a header field configured to include at least one switch labelto define a predetermined path from the source node 110 to thedestination node 112. A forwarding database may be maintained by eachintermediate node 130 that indicates which communication link 132, 134,136 should be used and in what priority to transmit the payload data fordelivery to the destination node 112. The forwarding database mayrepresent multiple paths to the destination address, and each of themultiple paths may include one or more cost values. Any technicallyfeasible type of cost value may characterize a link or a path within thenetwork system 100. In one embodiment, each node within the wirelessmesh network 102 implements substantially identical functionality andeach node may act as a source node, destination node or intermediatenode.

In network system 100, the access point 150 is configured to communicatewith at least one node within the wireless mesh network 102, such asintermediate node 130-4. Communication may include transmission ofpayload data, timing data, or any other technically relevant databetween the access point 150 and the at least one node within thewireless mesh network 102. For example, communications link 140 may beestablished between the access point 150 and intermediate node 130-4 tofacilitate transmission of payload data between wireless mesh network102 and network 152. The network 152 is coupled to the server 154 viacommunications link 142. The access point 150 is coupled to the network152, which may comprise any wired, optical, wireless, or hybrid networkconfigured to transmit payload data between the access point 150 and theserver 154.

In one embodiment, the server 154 represents a destination for payloaddata originating within the wireless mesh network 102 and a source ofpayload data destined for one or more nodes within the wireless meshnetwork 102. In one embodiment, the server 154 executes an applicationfor interacting with nodes within the wireless mesh network 102. Forexample, nodes within the wireless mesh network 102 may performmeasurements to generate measurement data, such as power consumptiondata. The server 154 may execute an application to collect themeasurement data and report the measurement data. In one embodiment, theserver 154 queries nodes within the wireless mesh network 102 forcertain data. Each queried node replies with requested data, such asconsumption data, system status and health data, and so forth. In analternative embodiment, each node within the wireless mesh network 102autonomously reports certain data, which is collected by the server 154as the data becomes available via autonomous reporting.

The techniques described herein are sufficiently flexible to be utilizedwithin any technically feasible network environment including, withoutlimitation, a wide-area network (WAN) or a local-area network (LAN).Moreover, multiple network types may exist within a given network system100. For example, communications between two nodes 130 or between a node130 and the corresponding access point 150 may be via a radio-frequencylocal-area network (RF LAN), while communications between access points150 and the network may be via a WAN such as a general packet radioservice (GPRS). As mentioned above, each node within wireless meshnetwork 102 includes a network interface that enables the node tocommunicate wirelessly with other nodes. Each node 130 may implement thefirst and/or second embodiments of the invention, as described above, byoperation of the network interface. An exemplary network interface isdescribed below in conjunction with FIG. 2.

FIG. 2 illustrates a network interface 200 configured to implementmulti-channel operation, according to one embodiment of the invention.Each node 110, 112, 130 within the wireless mesh network 102 of FIG. 1includes at least one instance of the network interface 200. The networkinterface 200 may include, without limitation, a microprocessor unit(MPU) 210, a digital signal processor (DSP) 214, digital to analogconverters (DACs) 220, 221, analog to digital converters (ADCs) 222,223, analog mixers 224, 225, 226, 227, a phase shifter 232, anoscillator 230, a power amplifier (PA) 242, a low noise amplifier (LNA)240, an antenna switch 244, and an antenna 246. A memory 212 may becoupled to the MPU 210 for local program and data storage. Similarly, amemory 216 may be coupled to the DSP 214 for local program and datastorage. Memory 212 and/or memory 216 may be used to store datastructures such as, e.g., a forwarding database, and/or routing tablesthat include primary and secondary path information, path cost values,and so forth.

In one embodiment, the MPU 210 implements procedures for processing IPpackets transmitted or received as payload data by the network interface200. The procedures for processing the IP packets may include, withoutlimitation, wireless routing, encryption, authentication, protocoltranslation, and routing between and among different wireless and wirednetwork ports. In one embodiment, MPU 210 implements the techniquesperformed by the node, as described in conjunction with FIGS. 1 and3-12B, when MPU 210 executes a firmware program stored in memory withinnetwork interface 200.

The MPU 214 is coupled to DAC 220 and DAC 221. Each DAC 220, 221 isconfigured to convert a stream of outbound digital values into acorresponding analog signal. The outbound digital values are computed bythe signal processing procedures for modulating one or more channels.The MPU 214 is also coupled to ADC 222 and ADC 223. Each ADC 222, 223 isconfigured to sample and quantize an analog signal to generate a streamof inbound digital values. The inbound digital values are processed bythe signal processing procedures to demodulate and extract payload datafrom the inbound digital values. Persons having ordinary skill in theart will recognize that network interface 200 represents just onepossible network interface that may be implemented within wireless meshnetwork 102 shown in FIG. 1, and that any other technically feasibledevice for transmitting and receiving data may be incorporated withinany of the nodes within wireless mesh network 102.

Referring generally to FIGS. 1-2, a given node 130 may be incorporatedinto a wide variety of different types of endpoint devices, includingcellular phones, smartphones, tablet computers, laptop computers,desktop computers, base stations, routers, smart television sets, powerdistribution meters, smart meters, and other mobile or stationarydevices configured to transmit and receive data across networks. Inaddition, a given node 130 may be coupled to many different types ofnetworks simultaneously, including, but not limited to, wireless meshnetwork 102, a cellular network, a WiFi™ network, a Bluetooth network,and any other technically feasible wired or wireless network.

A node 130 is configured to select between the different networks towhich that node is coupled and to then transmit and/or receive data onthe selected network. The node 130 selects a particular network based ondifferent sets of constraints. One set of constraints includes trafficconstraints that reflect traffic-oriented needs of applicationsexecuting on the endpoint device. Another set of constraints includesdevice constraints associated with the endpoint device or the node 130within that device. A third set of constraints includes networkconstraints associated with each of the various networks to which thenode 130 may be coupled. The node 130 is configured to prioritize thedifferent sets of constraints based on a current operating mode of thenode 130. The operating mode generally reflects current operatingconditions associated with the node 130, such as, e.g., a low power modethat reflects a low battery of the device, a high-reliability modetriggered by a particular type of traffic, a low-latency mode associatedwith a specific application, and so forth. Upon prioritizing the varioussets of constraints, the node 130 then rates the different networksbased on those prioritized constraints. The node 130 may then select anetwork on which to transmit and receive data based on the networkratings. This general approach is described in greater detail below inconjunction with FIGS. 3-12B.

Selecting Between Heterogeneous Networks

FIG. 3 illustrates a node within the network system of FIG. 1 coupled tomultiple heterogeneous networks, according to one embodiment of thepresent invention. As shown, node 130 is coupled to a network 310 thatincludes an access point (AP) 312. Node 130 is configured to joinnetwork 310 by establishing communication link 314 with AP 312. AP 312is configured to establish a communication link 316 with a destination330, thereby providing node 130 with a pathway to destination 330 viacommunication links 314 and 316. Destination 330 may be included withinnetwork 310.

As also shown, node 130 is coupled to a network 320 that includes an AP322. Node 130 is configured to join network 320 by establishingcommunication link 324 with AP 322. AP 322 is configured to establish acommunication link 326 with destination 330, thereby providing node 130with a pathway to destination 330 via communication links 324 and 326.Destination 330 may also be included within network 320.

Each of networks 310 and 320 may be any technically feasible type ofnetwork, including, for example, a wireless mesh network, a cellularnetwork, a WiFi™ network, a Bluetooth network, and so forth. Networks310 and 320 may be the same type of network and thus provide accessaccording to a common protocol. For example, networks 310 and 320 couldboth be WiFi™ networks. Alternatively, networks 310 and 320 may bedifferent types of networks and provide access according to differentprotocols. For example, network 310 could be a WiFi™ network whilenetwork 320 could be a cellular network.

Destination 330 represents a generic remote unit or collection of unitswith which node 130 is configured to establish communications. Forexample, destination 330 could be a remote server to which node 130transmits and/or receives data. In another example, destination 330could be an internet protocol (IP) network that node 130 relies upon foraccessing data, the Internet, or other devices coupled to that network.In yet another example, destination 330 could be a second node 130 withwhich node 130 is configured to communicate.

Node 130 is configured to establish communications with destination 330and to then route traffic to and from that destination. In doing so,node 130 is configured to select between networks 310 and 320 and thenroute traffic to and/or from destination 330 across the selectednetwork. In one embodiment, node 130 may select between networks 310 and320 for data transmission purposes, and then separately select betweennetworks 310 and 320 for data reception purposes. In another embodiment,node 130 may select between networks 310 and 320 separately for eachdifferent type of traffic node 130 is configured to route, e.g. whenoperating in a multi-network mode of operation.

As mentioned above, node 130 is configured to select between networks310 and 320 based on various sets of constraints associated withapplications that execute on node 130 (or on an endpoint device thatincludes node 130) and/or traffic associated with those applications,constraints associated with the endpoint device within which node 130resides, and constraints associated with networks 310 and 320.

The set of traffic constraints according to which node 130 selects anetwork could include, for example, a maximum hop count, a ratio of QoSto speed, a maximum latency value, a maximum timing jitter value, a linkquality indicator, a maximum number of retries, a minimum data rate, amaximum packet error rate, a received signal strength indicator (RSSI),a signal to noise ration (SNR), a minimum channel bandwidth, an optimalduty cycle, a load balancing objective, a need to bridge traffic betweenmultiple networks, and so forth. The set of device constraints couldinclude, for example, a maximum rate of power consumption, a maximumtransmit power, a roaming area, and so forth. The set of networkconstraints could include, for example, a power usage rate of thenetwork, a power saving technique associated with the network protocol,a cost per byte associated with the network, security features of thenetwork, and so forth.

Node 130 is configured to collect the aforementioned sets of constraintsand then prioritize those constraints based on the current operatingmode associated with node 130. For example, node 130 could determinethat the endpoint device that includes node 130 is currently operatingwith a low battery, and then prioritized power constraints over otherconstraints. Node 130 then computes a rating for each of networks 310and 320 based on the prioritized constraints. Node 130 could, forexample, compute a rating for network 310 by assigning a value to eachconstraint that reflects the degree to which network 310 meets thatconstraint, and then weight each value based on the prioritizationlevel. Node 130 could then accumulate the weighted values to compute therating for network 310. Once node 130 has computed a rating for each ofnetworks 310 and 320, node 130 then selects between those networks,based on the computed ratings, and routes traffic on the selectednetwork. FIGS. 4-6 illustrate exemplary heterogeneous networks in whichthe approach described thus far may be practiced, as described ingreater detail below.

FIG. 4 illustrates an exemplary scenario where node 130 of FIG. 3selects between heterogeneous networks based on performance metricsassociated with each network, according to one embodiment of the presentinvention. In the following exemplary scenario, node 130 operatesaccording to a high-throughput mode, which could, for example, betriggered by an application attempting to stream video data, among otherpossibilities.

As shown, node 130 resides within a multi-network system 400 thatincludes a cellular network 410, a smart utility network (SUN) 420,WiFi™ networks 430 and 440, a router 450, and an IP network 460.Cellular network 410 includes a cellular base station 412 configured toestablish and maintain cellular network 410. Node 130 may join cellularnetwork 410 by establishing a communication link (not shown) withcellular base station 412. SUN 420 includes a SUN AP 422 configured toestablish and maintain SUN 420. Node 130 may join SUN 420 byestablishing a communication link (not shown) with SUN AP 422. WiFi™networks 430 and 440 include WiFi™ APs 432 and 442, respectively. Node130 may join WiFi™ networks 430 and/or 440 by establishing acommunication links (none shown) with the respective WiFi™ APs 432 and442. In one embodiment, each of WiFi™ APs 432 and 442 provide multiplebasic service sets (BSSs) associated with different channels ordifferent bands. WiFi™ APs 432 and 442 are configured to establishcommunication links with a router 450 that provides access to IP network460.

IP network 460 represents an example of destination 330 shown in FIG. 3.Node 130 is configured to access IP network 460 via any of the networksto which node 130 is coupled. IP network 460 may be the Internet or theWorld Wide Web, among other possibilities. Node 130 is configured toselect between networks 410, 420, 430, and 440 by implementing thegeneral process described above in conjunction with FIG. 3.

In the specific context of FIG. 4, node 130 acquires traffic constraintsassociated with the video data that node 130 is configured to route,device constraints associated with an endpoint device that includes node130, and network constraints associated with each of networks 410, 420,430, and 440. Node 130 then prioritizes these different sets ofconstraints to reflect the high-throughput mode according to which node130 currently operates. Node 130 then rates each of networks 410, 420,430, and 440 based on the prioritized sets of constraints. In theexample shown, node 130 could determine that network 430 has the highestrating, indicating that network 430 best meets the prioritized sets ofconstraints. In particular, network 430 could provide the bestperformance for transporting video data. Upon selecting network 430,node 130 is configured to route the video data across that network.

FIG. 5 illustrates another exemplary scenario where the node of FIG. 3selects between heterogeneous networks based on a hop count associatedwith each network, according to one embodiment of the present invention.In the following exemplary scenario, a node 130-0 operates according toa traffic reduction mode, which could, for example, be triggered upondetecting that the various networks to which node 130-0 is coupled areexperiencing heavy traffic congestion.

As shown, node 130-0 resides within a multi-network system 500 thatincludes a mesh network 510 coupled to SUN 420 and router 450 of FIG. 4.Mesh network 510 includes an AP 512 as well as nodes 130-0 through130-2. Nodes 130-0 through 130-2 are interconnected with one another byvarious communication links, forming a mesh. Node 130-0 is configured tojoin mesh network 510 by establishing communication link 520 with AP 512as well as communication link 530 with node 130-1. Node 130-0 may thenaccess IP network 460 across communication links 520, 522, and 524 (3hops). As also shown, SUN 420 includes a node 130-4 that is configuredto join SUN 420 by establishing communication link 536 with SUN AP 422.Since node 130-0 is linked to node 130-4 by intermediate nodes 130-1 and130-2, node 130-0 may access IP network across communication links 530,532, 534, 536, and 538 (5 hops).

As mentioned above, in the exemplary scenario discussed herein node130-0 is configured to determine that mesh network 510 and SUN 420 arecongested with heavy traffic. In response, node 130-0 enters a trafficreduction mode. When selecting a network across which to route traffic,node 130 acquires traffic constraints, device constraints, and networkconstraints in the fashion mentioned above, and then prioritizes thosedifferent sets of constraints according to the traffic reduction mode.In so doing, node 130-0 may prioritize a hop count constraint aboveother constraints to reflect the need to reduce network traffic. Node130-0 then rates each network based on the prioritized constraints.Since mesh network 510 offers access to IP network 460 with a lower hopcount (3 hops) compared to that of SUN 420 (5 hops), mesh network 510better meets the various prioritized constraints, and, thus, node 130-0selects mesh network 510 for routing purposes.

FIG. 6 illustrates an exemplary scenario where the node of FIG. 3selects between heterogeneous networks based on timing constraintsassociated with transmitting data across each network, according to oneembodiment of the present invention. In the following exemplaryscenario, a node 130-0 operates according to a timing-sensitive mode,which could, for example, be triggered by an application attempting tostream latency or jitter-sensitive data, among other possibilities.

As shown, a basic service set (BSS) 600 includes AP 602 and nodes 130-0through 130-3. Nodes 130-0 through 130-3 are interconnected with oneanother, forming a mesh 610. Node 130-0 is coupled to node 130-1 bycommunication link 612, node 130-1 is coupled to node 130-2 bycommunication link 614, and node 130-2 is coupled to node 130-3 bycommunication link 616. Nodes 130-0 and 130-3 are coupled to AP 602 bycommunication links 620 and 622, respectively, thereby allowing thosenodes to communication with one another via AP 512.

In the exemplary scenario discussed herein, node 130-3 represents atarget destination for node 130-0. Node 130-0 could be configured totransmit data to node 130-3 or receive data from node 130-3, among otherexamples. Node 130-0 may be configured to route traffic to and/or fromnode 130-3 via mesh 610 or via BSS 600. Node 130-0 is configured toselect either BSS 600 or mesh 610 for routing purposes based onprioritized constraints, similar to above. Node 130-0 acquires traffic,device, and network constraints and then prioritizes those constraintsaccording to the timing-sensitive operating mode of node 130-0. Inparticular, node 130-0 prioritizes latency and jitter constraintsassociated with BSS 600 and mesh 610 above other constraints, and thenrates those networks based on the prioritized network constraints. Inthis example, mesh 610 provides lower jitter, despite requiring morehops from node 130-0 to node 130-3 compared to BSS 600. As such, node130-0 selects mesh 610 and routes traffic to node 130-3 viacommunication links 612, 614, and 616.

Referring generally to FIGS. 3-6, node 130 is configured to operatewithin a wide variety of different types of networks with diversearchitectures. Persons skilled in the art will recognize that theexemplary network architectures discussed thus far are provided forillustrative purposes only. In addition, node 130 may select between thevarious possible networks using a wide variety of different types ofconstraints, and may prioritize those constraints using any technicallyfeasible approach to ranking elements in a set. As described in greaterdetail below, FIG. 7 illustrates a generic approach to selecting betweennetworks, while FIGS. 8A-12B illustrate specific, exemplaryimplementations of that approach.

FIG. 7 is a flow diagram of method steps for selecting between differentheterogeneous networks associated with a node, according to oneembodiment of the present invention. Although the method steps aredescribed in conjunction with the systems of FIGS. 1-6, persons skilledin the art will understand that any system configured to perform themethod steps, in any order, is within the scope of the presentinvention.

As shown, a method 700 begins at step 702, where node 130 acquirestraffic constraints, device constraints, and network constraints. Thetraffic constraints reflect limitations associated with trafficgenerated or consumed by an application executed by the endpoint devicewhere node 130 resides, including, e.g. bandwidth needs or latencyrestrictions, etc. The device constraints reflect limitations associatedwith the endpoint device, including e.g. power restrictions, transmittersettings, etc. The network constraints reflect limitations associatedwith the various networks to which node 130 is coupled. When acquiringnetwork constraints at step 702, node 130 acquire a different set ofnetwork constraints for each different network.

At step 704, node 130 prioritizes the different sets of constraintsacquired at step 702 based on the current operating mode of node 130.The current operating mode of node 130 is derived from a set ofconditions that influence the functionality of node 130, includingapplication execution conditions, network traffic conditions,environmental conditions, and so forth. In one embodiment, node 130maintains a different set of prioritizations for each operating mode.Upon entering a given operating mode, node 130 retrieves prioritizedtraffic constraints, prioritized device constraints, and prioritizednetwork constraints associated with that operating mode. The prioritizednetwork constraints includes a different set of prioritized networkconstraints for each different network to which node 130 is coupled.

At step 706, node 130 computes a rating for each network to which node130 is coupled based on the prioritized constraints. The rating for agiven network reflects the degree to which the given network allows node130 to meet the prioritized network constraints associated with thatnetwork, as well as the prioritized traffic and device constraints. Inone embodiment, node 130 generates a score for each set of constraints,and then combines the scores to generate the network rating. To generatethe score for a given set of constraints, node 130 computes a value foreach constraint that reflects the degree to which that constraint ismet, and then weights the value based on the prioritization level ofthat constraint.

At step 708, node 130 compares the ratings for each network anddetermines which network has achieved the highest rating. At step 710,node 130 selects the highest rated network and then transmits and/orreceives data on that network. The method 700 may be repeatedperiodically, or when triggered by certain events. For example, whennode 130 changes locations or changes operating modes, the method 700may be repeated. By implementing the approach described above, node 130employs intelligent heuristics for selecting a network that reflect thereal-time operating state of the node, the state of applicationsexecuting thereon, and the state of the networks to which node 130 iscoupled.

Exemplary Scenarios of Selecting Between Heterogeneous Networks

The following FIGS. 8A-12B reflect exemplary use-cases where thetechniques described thus far may be applied. FIGS. 8A-8B reflect abasic, generic use case, while FIGS. 9A-12B reflect more specific usecases.

FIGS. 8A-8B illustrate data and processing engines implemented by thenode of FIG. 3 when selecting between heterogeneous networks accordingto an operating state of the node, according to one embodiment of thepresent invention. In FIG. 8A, a prioritization engine 820 within node130 acquires traffic constraints 802, device constraints 804, andnetwork constraints 806. Network constraints 806 include a different setof constraints for each network to which node 130 is coupled.Prioritization engine 820 also receives operating state 810 of node 130.Operating mode 810 of node 130 is derived from the current operatingconditions of node 130.

Based on operating mode 810, node 130 prioritizes traffic constraints802, device constraints 804, and network constraints 806 to generateprioritized traffic constraints 822, prioritized device constraints 824,and prioritized network constrains 826, respectively. Prioritizednetwork constraints 826 include a different set of prioritizedconstraints for each different network. The various prioritizedconstraints shown in FIG. 8A reflect default prioritizations for therespective constraints. Network selection and rating engine 840 thenreceives the various prioritized constraints.

In FIG. 8B, network selection and rating engine 840 computes networkratings 850 that include a different rating for each different network.By comparing the different network ratings, network selection and ratingengine 840 selects between available networks 830 to generate networkselection 860. Node 130 may than route traffic across the selectednetwork.

Node 130 is configured to adjust the default prioritizations shown inFIG. 8A based on different operating modes of node 130, as described ingreater detail below in conjunction with FIGS. 9A-12B.

FIGS. 9A-9B illustrate exemplary data and processing engines implementedby the node of FIG. 3 when selecting between a WiFi™ network and acellular network according to a high-throughput operating mode,according to one embodiment of the present invention. In FIG. 9A,prioritization engine 820 acquires traffic constraints 802, deviceconstraints 804, and network constraints 806, similar to FIG. 8A.Prioritization engine 820 also receives operating mode 910 of node 130,which indicates that node 130 operates in a high-throughput mode tosupport video streaming.

Based on operating mode 910, node 130 prioritizes traffic constraints802 and device constraints 804 to generate prioritized trafficconstraints 922 and prioritized device constraints 924, respectively.Prioritization engine 820 also prioritizes different network constraints806 associated with a WiFi™ network and a cellular network to which node130 is coupled to generate prioritized WiFi™ constraints 926-0 andprioritized cellular constraints 926-1, respectively. Network selectionand rating engine 840 then receives the various prioritized constraints.

In FIG. 9B, network selection and rating engine 840 computes differentnetwork ratings 950 for the WiFi™ network and the cellular network. Bycomparing the different network ratings, network selection and ratingengine 840 determines that the cellular network is rated higher than theWiFi™ network, indicating that the cellular network may supportoperating mode 910 more effectively than the WiFi™ network. Node 130 maythan route traffic across the cellular network.

In one embodiment, node 130 implements a decision process whereby node130 compares corresponding constraints associated with the WiFi™ networkand the cellular network. In doing so, node 130 first determines thatboth networks provide good security (first priority). Node 130 thendetermines that the WiFi™ provides higher bandwidth (second priority)than the cellular network, thereby favoring the WiFi™ network. However,node 130 then determines that the WiFi™ network is experiencing a muchhigher error rate than the cellular network (third priority), therebydisqualifying the WiFi™ network from consideration. Node 130 thereforeselects the cellular network.

FIGS. 10A-10B illustrate exemplary data and processing enginesimplemented by the node of FIG. 3 when selecting between a WiFi™ networkand a cellular network according to a low-battery operating mode,according to one embodiment of the present invention. In FIG. 10A,prioritization engine 820 acquires traffic constraints 802, deviceconstraints 804, and network constraints 806, similar to above.Prioritization engine 820 also receives operating mode 1010 of node 130,which indicates that node 130 operates in a high-throughput mode tosupport video streaming as well as a power conservation mode due to lowbattery.

Based on operating mode 1010, node 130 prioritizes traffic constraints802 and device constraints 804 to generate prioritized trafficconstraints 1022 and prioritized device constraints 1024, respectively.Prioritization engine 820 also prioritizes different network constraints806 associated with the WiFi™ network and the cellular network togenerate prioritized WiFi™ constraints 1026-0 and prioritized cellularconstraints 1026-1, respectively. Since node 130 operates according topower conservation mode, as well as high-throughput mode, prioritizedWiFi™ constraints 1026-0 and prioritized cellular constraints 1026-1dictate higher priorities for power related constraints, such astransmit power and power saving functions, compared to prioritized WiFi™constraints 926-0 and prioritized cellular constraints 926-1 shown inFIG. 9A. Network selection and rating engine 840 then receives thevarious prioritized constraints.

In FIG. 10B, network selection and rating engine 840 computes differentnetwork ratings 1050 for the WiFi™ network and the cellular network. Bycomparing the different network ratings, network selection and ratingengine 840 determines that the WiFi™ network is rated higher than thecellular network, indicating that the WiFi™ network may supportoperating mode 1010 more effectively than the cellular network. Node 130may than route traffic across the WiFi™ network.

In one embodiment, node 130 implements a decision process whereby node130 compares corresponding constraints associated with the WiFi™ networkand the cellular network. In doing so, node 130 first determines thatboth networks provide good security (first priority). Node 130 thendetermines that both networks support power saving functions (secondpriority). Node 130 then determines that the transmit power of the WiFi™network is 13 dB less than that of the cellular network, therebyaffording a significant power savings compared to the cellular networkand disqualifying the cellular network from consideration. Node 130therefore selects the WiFi™ network.

FIGS. 11A-11B illustrate exemplary data and processing enginesimplemented by the node of FIG. 3 when selecting between a WiFi™network, a cellular network, and a multi-hop mesh network according to alow-latency operating mode, according to one embodiment of the presentinvention. In FIG. 11A, prioritization engine 820 acquires trafficconstraints 802, device constraints 804, and network constraints 806,similar to above. Prioritization engine 820 also receives operating mode1110 of node 130, which indicates that node 130 operates in a controlsignal routing mode.

Based on operating mode 1110, node 130 prioritizes traffic constraints802 and device constraints 804 to generate prioritized trafficconstraints 1122 and prioritized device constraints 1124, respectively.Prioritization engine 820 also prioritizes different network constraints806 associated with the WiFi™ network, the cellular network, and themulti-hop mesh network to generate prioritized WiFi™ constraints 1126-0,prioritized cellular constraints 1126-1, and prioritized multi-hop meshnetwork constraints 1126-2, respectively. Network selection and ratingengine 840 receives the various prioritized constraints.

In FIG. 11B, network selection and rating engine 840 computes differentnetwork ratings 1150 for the WiFi™ network, the cellular network, andthe multi-hop mesh network. By comparing the different network ratings,network selection and rating engine 840 determines that the WiFi™network is rated higher than either of the other networks, indicatingthat the WiFi™ network may support operating mode 1110 more effectivelythan the other networks. Node 130 may than route traffic across theWiFi™ network.

In one embodiment, node 130 implements a decision process whereby node130 compares corresponding constraints associated with the variousnetworks to which node is coupled. In doing so, node 130 firstdetermines that all three networks provide good security (firstpriority). Node 130 then determines only the WiFi™ provides very lowlatency (fourth priority), thereby eliminating the cellular network andthe multi-hop mesh network from consideration. Node 130 thereforeselects the WiFi™ network.

FIGS. 12A-12B illustrate exemplary data and processing enginesimplemented by the node of FIG. 3 when selecting between a WiFi™network, a cellular network, and a multi-hop mesh network according to ahigh-reliability operating mode, according to one embodiment of thepresent invention. In FIG. 12A, prioritization engine 820 acquirestraffic constraints 802, device constraints 804, and network constraints806, similar to above. Prioritization engine 820 also receives operatingmode 1210 of node 130, which indicates that node 130 operates in ahigh-reliability operating mode.

Based on operating mode 1210, node 130 prioritizes traffic constraints802 and device constraints 804 to generate prioritized trafficconstraints 1222 and prioritized device constraints 1224, respectively.Prioritization engine 820 also prioritizes different network constraints806 associated with the WiFi™ network, the cellular network, and themulti-hop mesh network to generate prioritized WiFi™ constraints 1226-0,prioritized cellular constraints 1226-1, and prioritized multi-hop meshnetwork constraints 1226-2, respectively. Network selection and ratingengine 840 receives the various prioritized constraints.

In FIG. 12B, network selection and rating engine 840 computes differentnetwork ratings 1250 for the WiFi™ network, the cellular network, andthe multi-hop mesh network. By comparing the different network ratings,network selection and rating engine 840 determines that the multi-hopmesh network is rated higher than either of the other networks,indicating that the multi-hop mesh network may support operating mode1210 more effectively than the other networks. Node 130 may than routetraffic across the multi-hop mesh network.

In one embodiment, node 130 implements a decision process whereby node130 compares corresponding constraints associated with the variousnetworks to which node is coupled. In doing so, node 130 firstdetermines that all three networks provide good security (firstpriority). Node 130 then determines only the multi-hop mesh networkprovides high reliability (third priority), thereby eliminating theWiFi™ network and the cellular network from consideration. Node 130therefore selects the multi-hop mesh network.

In sum, a node within a wireless endpoint device may be coupled tomultiple heterogeneous networks simultaneously. The node is configuredto select between the different networks based on various constraintsassociated with the endpoint device, applications executing on theendpoint device, traffic routed by the endpoint device, and constraintsassociated with the multiple networks. Based on these differentconstraints, and based on the current operating mode of the node, thenode rates each network, and then selects the network with the highestrating to be used for routing purposes.

One advantage of the techniques set forth herein is that the endpointdevice may select the optimal network on which to perform communicationsbased on a wider range of environmental and operational factors comparedto traditional approaches. Accordingly, the endpoint device can beconfigured to maintain robust communication with other devices in manydifferent potential use-cases.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof. For example, aspects of thepresent invention may be implemented in hardware or software or in acombination of hardware and software. One embodiment of the inventionmay be implemented as a program product for use with a computer system.The program(s) of the program product define functions of theembodiments (including the methods described herein) and can becontained on a variety of computer-readable storage media. Illustrativecomputer-readable storage media include, but are not limited to: (i)non-writable storage media (e.g., read-only memory devices within acomputer such as CD-ROM disks readable by a CD-ROM drive, flash memory,ROM chips or any type of solid-state non-volatile semiconductor memory)on which information is permanently stored; and (ii) writable storagemedia (e.g., floppy disks within a diskette drive or hard-disk drive orany type of solid-state random-access semiconductor memory) on whichalterable information is stored. Such computer-readable storage media,when carrying computer-readable instructions that direct the functionsof the present invention, are embodiments of the present invention.

In view of the foregoing, the scope of the present invention isdetermined by the claims that follow.

The invention claimed is:
 1. A computer-implemented method for selectingbetween heterogeneous networks, the method comprising: acquiring a setof constraints associated with a network node; determining a currentoperating mode associated with the network node; prioritizing the set ofconstraints based on the current operating mode to generate a set ofprioritized constraints; generating a first rating for a first networkto which the network node is coupled based on the set of prioritizedconstraints; generating a second rating for a second network to whichthe network node is coupled based on the set of prioritized constraints;determining that the first rating exceeds the second rating; and causingthe network node to transmit or receive data on the first network. 2.The computer-implemented method of claim 1, wherein the set ofconstraints includes one or more constraints associated with datatraffic that the network node transmits or receives.
 3. Thecomputer-implemented method of claim 2, wherein the one or moreconstraints comprise a latency constraint associated with the datatraffic, and wherein the operating mode comprises a low-latencyoperating mode.
 4. The computer-implemented method of claim 1, whereinthe network node comprises an endpoint device, and the set ofconstraints includes one or more constraints associated with theendpoint device.
 5. The computer-implemented method of claim 4, whereinthe one or more constraints comprise a power consumption constraintassociated with the endpoint device, and wherein the operating modecomprises a power conservation mode.
 6. The computer-implemented methodof claim 1, wherein the set of constraints includes one or moreconstraints associated with the first network and one or moreconstraints associated with the second network.
 7. Thecomputer-implemented method of claim 6, wherein the one or moreconstraints associated with the first network comprise a first securityconstraint, the one or more constraints associated with the secondnetwork comprise a second security constraint, and wherein the operatingmode comprises a secure operating mode.
 8. The computer-implementedmethod of claim 6, wherein prioritizing the set of constraints comprisesprioritizing the one or more constraints associated with the firstnetwork to generate one or more first prioritized network constraints,and wherein generating the first rating comprises: weighting eachconstraint included in the one or more first prioritized networkconstraints based on an associated priority level to generate a firstset of weighted constraints; and accumulating the first set of weightedconstraints to generate the first rating.
 9. The computer-implementedmethod of claim 6, wherein prioritizing the set of constraints comprisesprioritizing the one or more constraints associated with the secondnetwork to generate one or more second prioritized network constraints,and wherein generating the second rating comprises: weighting eachconstraint included in the one or more second prioritized networkconstraints based on an associated priority level to generate a secondset of weighted constraints; and accumulating the second set of weightedconstraints to generate the first rating.
 10. A non-transitorycomputer-readable medium storing program instructions that, whenexecuted by a processing unit within a network node, cause theprocessing unit to select between heterogeneous networks, by performingthe steps of: acquiring a set of constraints associated with the networknode; determining a current operating mode associated with the networknode; prioritizing the set of constraints based on the current operatingmode to generate a set of prioritized constraints; generating a firstrating for a first network to which the network node is coupled based onthe set of prioritized constraints; generating a second rating for asecond network to which the network node is coupled based on the set ofprioritized constraints; determining that the first rating exceeds thesecond rating; and causing the network node to transmit or receive dataon the first network.
 11. The non-transitory computer-readable medium ofclaim 10, wherein the set of constraints includes one or moreconstraints associated with data traffic that the network node transmitsor receives.
 12. The non-transitory computer-readable medium of claim11, wherein the one or more constraints comprise a latency constraintassociated with the data traffic, and wherein the operating modecomprises a low-latency operating mode.
 13. The non-transitorycomputer-readable medium of claim 10, wherein the network node comprisesan endpoint device, and the set of constraints includes one or moreconstraints associated with the endpoint device.
 14. The non-transitorycomputer-readable medium of claim 13, wherein the one or moreconstraints comprise a power consumption constraint associated with theendpoint device, and wherein the operating mode comprises a powerconservation mode.
 15. The non-transitory computer-readable medium ofclaim 10, wherein the set of constraints includes one or moreconstraints associated with the first network and one or moreconstraints associated with the second network.
 16. The non-transitorycomputer-readable medium of claim 15, wherein the one or moreconstraints associated with the first network comprise a first securityconstraint, the one or more constraints associated with the secondnetwork comprise a second security constraint, and wherein the operatingmode comprises a secure operating mode.
 17. The non-transitorycomputer-readable medium of claim 15, wherein prioritizing the set ofconstraints comprises prioritizing the one or more constraintsassociated with the first network to generate one or more firstprioritized network constraints, and wherein generating the first ratingcomprises: weighting each constraint included in the one or more firstprioritized network constraints based on an associated priority level togenerate a first set of weighted constraints; and accumulating the firstset of weighted constraints to generate the first rating.
 18. Thenon-transitory computer-readable medium of claim 15, whereinprioritizing the set of constraints comprises prioritizing the one ormore constraints associated with the second network to generate one ormore second prioritized network constraints, and wherein generating thesecond rating comprises: weighting each constraint included in the oneor more second prioritized network constraints based on an associatedpriority level to generate a second set of weighted constraints; andaccumulating the second set of weighted constraints to generate thefirst rating.
 19. A system for selecting between heterogeneous networks,comprising: a memory unit storing program code comprising a softwareapplication; a processing unit coupled to the memory unit and configuredto execute the program code; and a network node coupled to theprocessing unit and coupled to the heterogeneous networks and configuredto route traffic associated with the software application across theheterogeneous networks by: acquiring a set of constraints associatedwith the network node, determining a current operating mode associatedwith the network node, prioritizing the set of constraints based on thecurrent operating mode to generate a set of prioritized constraints,determining that first traffic associated with the software applicationshould be routed on a first network included within the heterogeneousnetworks based on a first subset of the set of prioritized constraints,and determining that second traffic associated with the softwareapplication should be routed on a second network included within theheterogeneous networks based on a second subset of the set ofprioritized constraints.
 20. The system of claim 19, wherein the firstsubset includes one or more traffic constraints associated with thefirst traffic and one or more network constraints associated with thefirst network, wherein the second subset includes one or more trafficconstraints associated with the second traffic and one or more networkconstraints associated with the second network, and wherein theoperating mode comprises a multi-network mode.